I can even kill Mushrooms

well i'll give you some good news. If it was iodine poisoning, you would know it. If they aren't gone yet, they should be ok. I would suggest doing a small 10% water change though, it couldn't hurt. Since iodine is a small concentration element, a 10% change can drop it back into a tolerable range until you can get it tested.

 

YAY good news Ok I'll do the water change tonight. Thanks for the help!

 

Another thing to look at... Your water may not be " Off " ....

Your lights, And where you placed the corals..

When you first get mushrooms, They can be stressed some..
Just from moveing from tank to tank..
They have to get used to new lights, new water, etc..
Sometimes it just takes time.. If one is getting sort of pale, sounds like to much light..??
May need to move it lower till it gets used to its new tank, water, etc...
Your water can be ... Right on .... and this will happen..
Start out with mod to low light and the same for flow..

Good Luck, Larry

 

Definitely good advice here too. Softies and mushrooms tend to like less water flow, so put them into a lower flow area.